A Northern Ireland man who battered a pensioner to death with a hammer before going on to kill again has been told he will never be freed.

William McFall is one of two convicted killers who tortured and murdered a Vietnamese mother-of-two while out on licence.

McFall (51), originally from Graymount Parade in Greencastle, Co Antrim, and 40-year-old Stephen Unwin murdered nail technician Quyen Ngoc Nguyen last August after a four-hour ordeal and dumped her body in her car before torching it.

Newcastle Crown Court heard she had been lured to Unwin's home in Shiney Row near Sunderland, where McFall lay in wait.

Unwin raped the 28-year-old, who was just 5ft and weighed seven stone. Mr Justice Morris ruled the pair should never be released, sentencing both to whole-life jail terms.

They join a group of notorious killers, including Yorkshire Ripper Peter Sutcliffe and serial killers Rose West and Dennis Nilsen, who will die behind bars.

The judge said: "William John McFall, you are an extremely violent man capable of monstrous behaviour."

McFall shouted angrily from the dock: "That's your personal opinion." In May 1996, McFall murdered Greenisland pensioner Martha Gilmore by beating her to death with a hammer.

He brutally attacked his victim after she disturbed him breaking into her home. He was jailed for life and released on licence in October 2010.

Unwin had a history of setting fires to destroy evidence at the scenes of his crimes.

He too beat a pensioner to death during a break-in at his home on Christmas Day 1998 and the fire he started to cover his tracks meant the victim could only be identified by his medical records.

Unwin admitted murder, was sentenced to life and was released on licence in December 2012. He had met McFall in prison. Jamie Hill QC told the court: "In cases where a defendant has been convicted of murder for a second time, normally the starting point for sentence would be a whole life order.

"In the common parlance, life without parole."

The court heard how the pair ate curry as their victim lay lifeless on the floor before they dumped her in the burning car by allotments.

The killers took £1,000 from her bank accounts, having tortured her for the PINs.

Dapinder Singh QC, for Unwin, urged the judge not to impose a whole life tariff.

Nicholas Lumley QC, for McFall, said his client continued to deny the murder and regretted coming into contact with Unwin after his release as his life was "on track" in Blackpool.

The pair worked together in the north-east of England maintaining properties for landlords - and also stealing cannabis from drugs farms.

Mr Lumley said: "He (McFall) attributes his involvement in this terrible incident to his weakening to Mr Unwin's charms."

The victim's sister, 35-year-old Quynh Ngoc Nguyen read an impact statement in court, saying: "We cannot comprehend how men like this can live freely in this country.

"My sister believed, as I did, that you came to this country for a safer life, with better opportunities for herself and her children."